Frontpage extensions are no longer supported due to the fact that this software has been discontinued by Microsoft in 2006. And recently, FrontPage support has been dropped by cPanel as well. Most hosting companies do not support this technology as well, and those few who still do, are most likely already in the process of discontinuing support.
Frontpage can still be used for publishing websites, please see the link below:
http://support.microsoft.com/kb/143101/en-us
There are also numerous modern alternatives to Frontpage available, you can search for them online.